This invention relates to aqueous peroxide gel dentifrice compositions which are stable with respect to both peroxide level and viscosity. Said compositions comprising an aqueous peroxide, a polyol or mixtures of polyols, a gelling agent and a stabilizer. More particularly, the invention relates to dentifrice gels including aqueous hydrogen peroxide which are viscosity stable and resistant to loss of available oxygen.
Aqueous hydrogen peroxide is a well-known antiseptic material which has been widely used in the topical treatment of infectious processes. In addition, aqueous hydrogen peroxide has also been found to be useful in mouthwashes, dentifrices and oral prophylaxis generally.
Periodontists are in general agreement that substantively placing oxygen on the gums via peroxide compounds has salutory effects with respect to periodontal disorders such as gingivitis.
The rationale for this treatment is that the disorders are believed to be caused by infectious anaerobic microorganisms which are active in the absence of oxygen. The anaerobic microorganisms can be controlled or eliminated entirely by the application of compounds containing active oxygen or peroxy compounds which will readily release oxygen. The presence of oxygen creates an aerobic atmosphere which is antagonistic to the anaerobic microorganisms.
Dentifrices, especially toothpastes and powder containing active oxygen or hydrogen peroxide liberating ingredients such as peroxides, percarbonates and perborates of the alkali and alkaline earth metals or complex compounds containing hydrogen peroxide with salts of the alkali or alkaline earth metals have been known and used for some time. However, the products previously available have been found to suffer from several serious drawbacks. Principal among which is the tendency of these products to decompose within a relatively short period of time following manufacture with concomitant loss of all or a substantial amount of the available oxygen. The peroxy compounds are notoriously unstable with respect to maintenance of peroxide level as well as viscosity and have been found to be difficult to formulate into aqueous solutions or pastes which will have an adequate shelf-life and yet will readily liberate oxygen when applied to the oral cavity. Therefore, prior to the present invention, oxygen liberating compositions for the treatment of periodontal disorders or conditions have usually been formulated as anhydrous powders or water-free pastes, ointments, etc., which must be protected against contamination and chemical interaction. Additionally, these formulations have been found to be difficult or inconvenient to use since chemically reactive components are usually packaged separately and dosage cannot be easily regulated.
It has also been proposed to employ hydrogen peroxide solutions in the prophylaxis and therapy of periodontal disorders and conditions. However, these solutions have been found to be too fluid to permit effective massaging of the solution on the infected areas of the gingiva. Further, presently available hydrogen peroxide solutions, due to their extreme evanescent qualities tend to provide no more than transient aerobic conditions in the oral cavity.
In addition, considerable attempts have been made previously to provide stable peroxide gels having a concentration of up to about 15% by weight hydrogen peroxide such as disclosed in U.S. Pat. No. 3,639,574. These gel systems have been generally used in hair bleaching and the treatment of cuts and are not suggested for use in dentifrice and oral prophylaxis compositions.